Head unit, electrospinning head, and electrospinning apparatus

ABSTRACT

According to one embodiment, an electrospinning head includes a plurality of head units and a coupling structure, and the plurality of head units are coupled to one another through the coupling structure. Each head unit includes a unit main body and a nozzle. Inside the unit main body, a hollow storing a raw material liquid is formed along a longitudinal axis. The nozzle is formed of a conductive material and provided on an outer circumferential surface of the unit main body. The nozzle ejects the raw material liquid supplied through the hollow of the unit main body. The coupling structure connects the plurality of head units in a state where the hollows of the unit main bodies communicate with one another.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2019-044870, filed Mar. 12, 2019; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate to a head unit, an electrospinninghead, and an electrospinning apparatus.

BACKGROUND

There exists an electrospinning apparatus which deposits fine fiber on asurface of a collection body or substrate via an electrospinning method(sometimes referred to as an “electric spinning method” or“charge-induced spinning method”) to form a film of fiber. Theelectrospinning apparatus includes an electrospinning head, including ahead body and a nozzle. The electrospinning head is provided with ahollow (head flow passage) for storing a raw material liquid inside thehead body, and the nozzle on an outer circumference surface of the headbody. The raw material liquid is ejected from an ejection port of thenozzle toward the surface of the collection body or substrate to depositthe fiber on the surface of the collection body or substrate, via theapplication of a voltage between the electrospinning head and thecollection body or substrate.

In the electrospinning apparatus described above, when fiber isdeposited on a surface of a substrate having a large size in its widthdirection, a film of the fiber having a large size in its widthdirection may be formed via the electrospinning method. Even when a filmof the fiber having a large size in its width direction is formed, anelectrospinning apparatus is required to appropriately deposit the fiberon a surface of a substrate or the like, and appropriately form a filmof the fiber. The electrospinning apparatus is also required to suppressthe complexity of its configuration and its control system, and tosuppress an increase in manufacturing costs and a reduction inproductivity of its electrospinning head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an example of an electrospinningapparatus according to a first embodiment;

FIG. 2 is a perspective diagram schematically showing an electrospinninghead according to the first embodiment;

FIG. 3 is a schematic diagram showing the electrospinning head accordingto the first embodiment when viewed from a direction crossing thelongitudinal axis of the head;

FIG. 4 is a cross-sectional diagram schematically showing theelectrospinning head according to the first embodiment at across-section parallel or substantially parallel to the longitudinalaxis of the head;

FIG. 5 is a cross-sectional diagram schematically showing theelectrospinning head according to the first embodiment at across-section perpendicular or substantially perpendicular to thelongitudinal axis of the head;

FIG. 6 is a perspective diagram schematically showing an electrospinninghead according to a first modification;

FIG. 7 is a schematic diagram showing the electrospinning head accordingto the first modification when viewed from a direction crossing thelongitudinal axis of the head;

FIG. 8 is a cross-sectional diagram schematically showing theelectrospinning head according to the first modification at across-section parallel or substantially parallel to the longitudinalaxis of the head;

FIG. 9 is a cross-sectional diagram schematically showing theelectrospinning head according to the first modification at across-section perpendicular or substantially perpendicular to thelongitudinal axis of the head;

FIG. 10 is a schematic diagram showing an electrospinning head accordingto a second modification in a state where head units are separated fromeach other;

FIG. 11 is a cross-sectional diagram schematically showing theelectrospinning head according to the second modification at across-section parallel or substantially parallel to the longitudinalaxis of the head;

FIG. 12 is a schematic diagram showing an electrospinning head accordingto a third modification when viewed from a direction crossing thelongitudinal axis of the head;

FIG. 13 is a schematic diagram showing the electrospinning headaccording to the third modification when viewed from one side of thedirection along the longitudinal axis; and

FIG. 14 is a schematic diagram showing an electrospinning head accordingto a fourth modification.

DETAILED DESCRIPTION

According to an embodiment, the head unit includes a unit main body anda nozzle. Inside the unit main body, a hollow configured to store a rawmaterial liquid is formed along the longitudinal axis of the unit mainbody. The nozzle is formed of a conductive material and provided on anouter circumferential surface of the unit main body. The nozzle isconfigured to eject the raw material liquid supplied through the hollowof the unit main body. The head unit includes a coupling structure. Thecoupling structure is capable of coupling another head unit to the headunit, on at least one side of the head unit, in the direction along thelongitudinal axis. The coupling structure couples a unit main body ofanother head unit to the unit main body in a state where the hollow ofthe unit main body communicates with a hollow of the unit main body ofsaid another head unit. A head flow passage is then formed by the hollowof the unit main body and the hollow of said another head unitcommunicating with the hollow of the unit main body.

According to another embodiment, the electrospinning head includes aplurality of head units and a coupling structure, and the plurality ofhead units are arranged along the longitudinal axis. The plurality ofhead units are coupled to one another through the coupling structure.Each head unit includes a unit main body and a nozzle. Inside the unitmain body, a hollow configured to store a raw material liquid is formedalong the longitudinal axis. The nozzle is formed of a conductivematerial and provided on an outer circumferential surface of the unitmain body. The nozzle is configured to eject the raw material liquidsupplied through the hollow of the unit main body. The couplingstructure connects the plurality of head units in a state where thehollows of the unit main bodies communicate with one another. A headflow passage is formed along the longitudinal axis by the hollowscommunicating with one another.

According to another embodiment, an electrospinning apparatus includesthe electrospinning head, a supply source, and an electric power source.The supply source supplies a raw material liquid to the head flowpassage of the electrospinning head. The electric power source applies avoltage to the electrospinning head.

Hereinafter, the embodiments will be described with reference to thedrawings.

First Embodiment

FIG. 1 shows an example of an electrospinning apparatus 1 according to afirst embodiment. As shown in FIG. 1, the electrospinning apparatus 1includes an electrospinning head 2, a supply source (supply section) 3of a raw material liquid, an electric power source 4, a collection body5, and a controller 6.

FIGS. 2 to 5 respectively show the configuration of the electrospinninghead 2. As shown in FIGS. 1 to 5, the electrospinning head 2 has alongitudinal axis C as a central axis, and extends along thelongitudinal axis C. The electrospinning head 2 includes a head mainbody 11 and a plurality of nozzles 12 (four nozzles in the presentembodiment). In the electrospinning head 2, as many connectors 13 asthere are nozzles 12 are provided, and each nozzle 12 is connected tothe head main body 11 via one corresponding connector 13. In the presentembodiment, the head main body 11, nozzles 12 and connectors 13 arerespectively formed of a conducting material.

The number of the nozzles 12 is not particularly limited. The connectors13 are not necessarily provided, and each nozzle 12 may be directlyconnected to the head body 11. Furthermore, each of the head main body11, nozzles 12, and connectors 13 is preferably formed of a materialhaving resistance to a raw material liquid (to be described later), forexample, stainless steel. Here, FIG. 2 is a perspective diagram and FIG.3 shows a state where the electrospinning head is viewed from adirection crossing (perpendicular or substantially perpendicular to) thelongitudinal axis C. FIG. 4 shows a cross-section parallel orsubstantially parallel to the longitudinal axis C, and FIG. 5 shows across-section perpendicular or substantially perpendicular to thelongitudinal axis C.

The respective nozzles 12 are provided on an outer circumferentialsurface of the head main body 11. The outer circumferential surface ofthe head main body 11 extends around the longitudinal axis C and forms apart of an exterior surface of the head main body 11. The outercircumferential surface of the head main body 11 faces the side awayfrom the longitudinal axis C, in a direction crossing the longitudinalaxis C. In the present embodiment, the plurality of nozzles 12 arearranged at the same or substantially the same angular positions withrespect to one another around the longitudinal axis C. For this reason,in the present embodiment, the plurality of nozzles 12 are arrangedalong the longitudinal axis C to form a nozzle row 15. Each nozzle 12protrudes to the outer circumference side on the outer circumferentialsurface of the head main body 11.

Inside the head main body 11, a head flow passage 16 is formed along thelongitudinal axis C. In the present embodiment, the head flow passage 16is formed coaxially or substantially coaxially with the head main body11, and the central axis of the head flow passage 16 is formed coaxiallyor substantially coaxially with the longitudinal axis C. Also, the headflow passage 16 is formed across the entirety or the majority of thehead main body 11 in the direction along the longitudinal axis C.Therefore, in the present embodiment, the head main body 11 is formedinto a cylindrical shape, provided with the head flow passage 16 as aninternal hollow.

In the electrospinning head 2, as many nozzle flow passages 17 as thereare nozzles 12 are formed, and one corresponding nozzle flow passage 17is formed inside of each nozzle 12. Each nozzle flow passage 17communicates with the head flow passage 16 and extends toward the outercircumference side of the head main body 11 from the head flow passage16. Each nozzle flow passage 17 opens externally at its ejection port18. In each nozzle 12, an ejection port 18 is formed at a projecting endfrom the head main body 11.

Each nozzle 12 is, for example, a needle nozzle. The outer diameter ofeach nozzle 12 is not particularly limited; however, it is preferably assmall as possible. By reducing the outer diameter of each respectivenozzles 12, an electric field concentration tends to take place in thevicinity of the respective ejection ports 18 of the nozzles 12 when avoltage is applied between the electrospinning head 2 and the collectionbody 5, as described later. The generation of the electric fieldconcentration in the vicinity of the respective ejection ports 18 of thenozzles ensures a high electric field intensity between each nozzle 12and the collection body 5, even when the voltage applied between theelectrospinning head 2 and the collection body 5 is lowered. In anexample, the outer diameter of each nozzle 12 is, for example, about 0.3mm or larger and 1.3 mm or smaller.

The opening size of each ejection port 18 is not particularly limited,as long as it is within a range smaller than the outer diameter of eachnozzle 12. Each opening size of the ejection ports 18 is properly setcorresponding to the type, etc. of fiber 100 to be deposited on asurface of the collection body 5. In an example, each opening size ofthe ejection ports 18 is, for example, about 0.1 mm or larger and 1 mmor smaller.

The supply source 3 of the raw material liquid includes a reservoir 31,a supply driver 32, a supply adjuster 33, and a supply pipe 35. Thereservoir 31, supply driver 32, supply adjuster 33, and supply pipe 35respectively have resistance to the raw material liquid. In an example,the reservoir 31 and the supply pipe 35 are respectively formed of aninsulating material, such as a fluorine resin.

The reservoir 31 is a tank or the like to store a raw material liquid.In the raw material liquid, a polymer material is dissolved in asolvent. The polymer contained in the raw material liquid and thesolvent to dissolve the polymer are properly determined so as tocorrespond to the type, etc. of the fiber 100 to be deposited on asurface of the collection body 5. The supply pipe 35 connects thereservoir 31 and the head main body 11 of the electrospinning head 2. Aflow passage of the raw material liquid is formed inside the supply pipe35.

An inflow port 22 is formed at one end of the head flow passage 16 ofthe head main body 11. The supply pipe 35 is connected to the head mainbody 11 at the inflow port 22, and the head flow passage 16 communicateswith the inside of the supply pipe 35 at the inflow port 22. In thepresent embodiment, the inflow port 22 is formed on one end face of thehead main body 11, in the direction along the longitudinal axis C. Theother end of the head flow passage 16, i.e., the opposite end of thehead flow passage 16 to the inflow port 22 in the head flow passage 16,closes to the outside of the head main body 11. In an example, the otherend of the head flow passage 16 is closed by the head main body 11itself, and in another example, the other end of the head flow passage16 is closed by a lid member, etc. attached to the head main body 11.

The supply driver 32 is driven to thereby supply the raw material liquidfrom the reservoir 31 to the head flow passage 16 of the head main body11 through the supply pipe 35. In an example, the supply driver 32 is apump. In another example, the supply driver 32 pressure-feeds the rawmaterial liquid from the reservoir 31 to the head flow passage 16 bysupplying a gas to the reservoir 31.

The supply adjuster 33 adjusts the rate of flow, pressure, etc. of theraw material liquid supplied to the head flow passage 16. In an example,the supply adjuster 33 is a control valve capable of controlling therate of flow, pressure, etc. of the raw material liquid. The supplyadjuster 33 constrains the ejection of the raw material liquid from therespective ejection ports 18 of the nozzles 12 by adjusting the rate offlow, pressure, etc. of the raw material liquid. The supply adjuster 33adjusts the rate of flow, pressure, etc. of the raw material liquid toappropriate values based on the viscosity of the raw material liquid,respective sizes of the ejection ports 18, etc. Furthermore, in anexample, the supply adjuster 33 is switchable between supplying and notsupplying the raw material liquid from the reservoir 31 to the head flowrate 16. In this case, the supply adjuster 33 is, for example, a switchvalve.

The supply driver 32 and supply adjuster 33 need not necessarily beprovided. In an example, the reservoir 31 is provided on the verticallyupper side, with respect to the head main body 11 to supply the rawmaterial liquid from the reservoir 31 to the head flow passage 16 byutilizing gravitational force. In this case, the ejection of the rawmaterial liquid from the respective ejection ports 18 of the nozzles 12is constrained in a state where no voltage is applied between theelectrospinning head 2 and the collection body 5 by adjusting thedifference in height of the reservoir 31 with respect to the head mainbody 11.

The electric power source 4 applies a voltage between theelectrospinning head 2 and the collection body 5. In this case, in theelectrospinning head 2, a voltage with predetermined polarity is appliedto the each nozzle 12 via the head main body 11 and one correspondingconnector 13. In an example, a terminal (not shown) electricallyconnected to each nozzle 12 is provided, and a voltage is applied toeach nozzle 12 via the terminal. In a configuration where a terminal(s)is provided, the head main body 11 and the connectors 13 need not beformed of a conductive material. As described above, it suffices thatthe electric power source 4 is configured to apply a voltage to eachnozzle 12.

The nozzles 12 are electrically connected to each other. Therefore, in astate where a voltage is applied to each nozzle 12, the nozzles 12 cometo have identical or substantially identical electric potential to oneanother. The voltage applied to each nozzle 12 may have a positivepolarity or negative polarity. In the example shown in FIG. 1, theelectric power source 4 is a direct-current electric power source andapplies a positive voltage to each nozzle 12.

The collection body 5 is formed of a conductive material. The collectionbody 5 has resistance to the raw material liquid, and in an example, itis formed of stainless steel. The collection body 5 is disposed on theside where each of the ejection ports 18 opens with respect to theelectrospinning head 2. Therefore, the collection body 5 is disposed onthe side where the raw material liquid is ejected from the ejectionports 18 with respect to the electrospinning head 2.

In the example of FIG. 1, the collection body 5 is grounded. For thisreason, in a state where a positive voltage is applied to each nozzle12, the voltage to ground of the collection body 5 becomes OV orsubstantially OV. In another example, the collection body 5 is notgrounded. The electric power source 4 applies, to the collection body 5,a voltage with counter-polarity to that of each nozzle 12.

In a state where the raw material liquid is supplied to theelectrospinning head 2 by the supply source 3, the raw material liquidis ejected from each ejection port 18 of the nozzles 12 toward thecollection body 5 by applying a voltage between each nozzle 12 and thecollection body 5 by means of the electric power source 4, as describedabove. In other words, the raw material liquid is ejected toward thecollection body 5 by an electric potential difference between eachnozzle 12 and the collection body 5. The raw material liquid is ejectedfrom each ejection port 18 of the nozzles 12 toward the collection body5, so that fiber 100 is deposited on the surface of the collection body5, and a film of the fiber 100 is formed by the deposited fiber 100.That is, a film of the fiber 100 is formed by an electrospinning method(which may be referred to as an “electric spinning method” or“charge-induced spinning method”).

The voltage applied between the electrospinning head 2 and thecollection body 5, i.e., an electric potential difference between eachnozzle 12 and the collection body 5, is adjusted to a suitable size,corresponding to the kind of polymer contained in the raw materialliquid and the distance from each nozzle 12 to the collection body 5,etc. In an example, a 10 kV or higher and 100 kV or lower directcurrent-voltage is applied between each nozzle 12 and the collectionbody 5. In an example, the direction along the longitudinal axis C ofthe electrospinning head 2 is identical or substantially identical tothe width direction of the collection body 5. The width direction of aformed film of the fiber 100 is identical or substantially identical tothe direction along the longitudinal direction C of the electrospinninghead 2.

The collection body 5 is formed into a plate or sheet. When thecollection body 5 is formed into a sheet, the fiber 100 may be depositedon a collection body 5 wound to the outer circumferential surface of aroll or the like. The collection body 5 may be movable.

In an example, a pair of rotating drums and a driving source to drivethe rotating drums are provided. The rotating drums are driven by thedriving source, so that the collection body 5 moves between the pair ofrotating drums in a similar manner to that of a conveyor belt. In thiscase, for example, the moving direction (conveying direction) of thecollection body 5 crosses (becomes perpendicular or substantiallyperpendicular to) the width direction of the collection body 5. Themovement (conveyance) of the collection body allows a region in whichthe fiber 100 is deposited on the surface of the collection body 5 tochange depending on time. With this configuration, the fiber 100 can becontinuously deposited on the collection body 5 depending on time, and afilm of the fiber 100 as a deposit of the fiber 100 is efficientlymanufactured.

The film of the fiber 100 formed on the surface of the collection body 5is removed from the collection body 5. The film of the fiber 100 is notlimited thereto; however, it is used for an unwoven fabric, a filter,and the like.

In an example, the collection body 5 is not provided. In this case, asubstrate formed of a conductive material is used, and a voltage isapplied between each nozzle 12 and the substrate, so that the rawmaterial liquid is ejected from each ejection port 18 of the nozzles 12toward the substrate. A film of the fiber 100 is then formed on asurface of the substrate by depositing the fiber 100 on the surface ofthe substrate. In this case, the substrate may be grounded, and avoltage with counter-polarity to that of each nozzle 12 may be appliedto the substrate by the electric power source 4.

In another example, a substrate is placed on the collection body 5, anda voltage is applied between each nozzle 12 and the collection body 5 asdescribed above. The fiber 100 is deposited on a surface of thesubstrate placed on the collection body 5 to form a film of the fiber100 on the surface of the substrate. In this case, even when thesubstrate has electrically insulating properties, a film of the fiber100 can be formed on the surface of the substrate.

When the substrate is placed on the collection body 5, the substrate maybe movable on the collection body 5. In an example, a rotating drumaround which a sheet-like substrate is wound and a rotating drum whichwinds up the substrate in which a film of the fiber 100 is formed on thesurface are provided. Each drum rotates, so that the substrate moves onthe collection body 5. At that time, for example, the moving direction(conveying direction) of the substrate crosses (is perpendicular orsubstantially perpendicular to) the width direction of the substrate.The movement (conveyance) of the substrate allows a region in thesurface of the substrate where the fiber 100 is deposited to changedepending on time. With this configuration, the fiber 100 can becontinuously deposited on the substrate depending on time, and a film ofthe fiber 100 as a deposit of the fiber 100 is efficiently manufactured.

An example of forming a film of the fiber 100 on a surface of thesubstrate is not limited thereto and includes the manufacture of aseparator integrated electrode for batteries. In this case, one of anegative electrode and a positive electrode in an electrode group isused as a substrate. A film of the fiber 100 formed on a surface of thesubstrate will be a separator integrated with a negative or positiveelectrode.

A controller 6 is, for example, a computer, etc. The controller 6includes a processor or an integrated circuit (control circuit)including a central processing unit (CPU), an application-specificintegrated circuit (ASIC) or a field-programmable gate array (FPGA),etc., and a storage medium, such as a memory. The controller 6 mayinclude only one integrated circuit, etc. or a plurality of integratedcircuits, etc. The controller 6 executes a program, etc. stored in thestorage medium, etc. to thereby perform processing. The controller 6controls driving of the supply driver 32, actuation of the supplyadjuster 33, output from the electric power source 4, etc.

As shown in FIGS. 2 to 5, the electrospinning head 2 includes aplurality of head units 21A, 21B (two in the present embodiment). Thehead units 21A, 21B are arranged along the longitudinal axis C. The headunits 21A, 21B are coupled to each other. In the present embodiment, thetwo head units 21A, 21B are coupled, so that the electrospinning head 2is formed. The other head unit 21B is coupled to the head unit 21A onone side in a direction along the longitudinal axis C. For this reason,in the present embodiment, the head units 21A and 21B are adjacent toeach other in the direction along the longitudinal axis C.

Each of the head units 21A and 21B includes a unit main body 23. Eachhead main body 23 extends with the longitudinal axis C as a centralaxis. In the electrospinning head 2, a head main body 11 is formed ofthe unit main bodies 23 of the head units 21A, 21B. The outercircumferential surface of the head main body 11 is formed of the outercircumferential surfaces of the unit main bodies 23 of the head units21A, 21B. In addition, the head units 21A, 21B are coupled in a statewhere the unit main bodies 23 of the head units 21A and 21B are coaxialor substantially coaxial with each other.

In each of the head units 21A, 21B, a hollow 25 is formed along thelongitudinal axis C inside of the unit main body 23. In each of the headunits 21A, 21B, the hollow 25 is formed coaxially or substantiallycoaxial with the unit main body 23, and the central axis of the hollow25 is formed coaxially or substantially coaxial with the longitudinalaxis C. In the electrospinning head 2, the head units 21A, 21B arecoupled in a state where the hollows 25 of the unit main bodies 23 ofthe head units 21A, 21B communicate with each other. The head flowpassage 16 is then formed along the longitudinal axis C by the hollows25 of the unit main bodies 23 of the head units 21A, 21B.

In each of the head units 21A and 21B, the nozzle 12 described above isarranged on the outer circumferential surface of the unit main body 23.In an example of FIG. 2, etc., two nozzles 12 are provided in the headunit 21A, and two nozzles 12 are provided in the head unit 21B. Thenumber of nozzles 12 provided in each of the head units 21A, 21B is notparticularly limited, and it suffices that one or more nozzles 12 areconnected to each unit main body 23 of the head units 21A, 21B.

In the example of FIG. 2, etc., an end face of the head main body 11 onone side in the direction along the longitudinal axis C is formed of theunit main body 23 of the head unit 21A, and the other end face of thehead main body 11 on the other side in the direction along thelongitudinal axis C is formed of the unit main body 23 of the head unit21B. An inflow port 22 of the head flow passage 16 is formed in the headunit 21A.

A sealing member 20 is provided between the adjacent head units 21A, 21Badjacent in the direction along the longitudinal axis C. Therefore, thesealing member 20 is placed on a coupling face P of the adjacent headunits 21A, 21B. The sealing member 20 is, for example, a washer or ring,etc. An example of a material forming the sealing member 20 includespolytetrafluoroethylene (PTFE). The sealing member 20 maintains a spacebetween the unit main bodies 23 of the head units 21A and 21B in aliquid-tight manner at the coupling face P. This configuration preventsthe raw material liquid from flowing out from the head flow passage 16to the outside of the head main body 11.

The coupling face P passes by a position away from each nozzle 12. Inthe present embodiment, the coupling face P is perpendicular orsubstantially perpendicular to the longitudinal axis C. A normal linedirection (direction shown by arrows N1 and N2) of the coupling face Pis identical or substantially identical to the direction along thelongitudinal axis C, and is parallel or substantially parallel to thelongitudinal axis C.

Here, a coupling structure (coupling) that couples the head units 21A,21B to each other will be described. In each unit main body 23 of thehead units 21A and 21B, one or more holes 26 are formed along thelongitudinal axis C. In the present embodiment, three holes 26 areformed in each of the head units 21A, 21B. In each of the head units 21Aand 21B, each hole 26 penetrates through the unit main body 23 in thedirection along the longitudinal axis C. In each of the head units 21Aand 21B, the holes 26 are respectively formed on the inner circumferenceside with respect to the outer circumferential surface of the unit mainbody 23 and nozzles 12, and are formed between the hollow 25 and theouter circumferential surface of the unit main body 23 in the radialdirection of the unit main body 23.

In each of the head units 21A and 21B, the holes 26 are formed away fromone another around the longitudinal axis C. In an example, the holes 26are arranged at regular or substantially regular intervals around thelongitudinal axis C. In addition, each hole 26 of the head unit 21A isarranged at the same or substantially the same angular position with onecorresponding hole 26 in the head unit 21B in a direction around thelongitudinal axis C.

In the present embodiment, as many holes 27 as there are holes 26 formedin the head unit 21A, i.e., as many as the holes 26 formed in the headunit 21B, are formed in the sealing member 20. Each hole 27 penetratesthrough the sealing member 20 in the direction along the longitudinalaxis C. Each hole 27 is arranged at the same or substantially the sameangular position with one corresponding hole 26 in the head unit 21A andone corresponding hole 26 in the head unit 21B around the longitudinalaxis C. In the head main body 11, each hole 26 of the head unit 21Acommunicates with one corresponding hole 26 in the head unit 21B via onecorresponding hole 27 in the sealing member 20.

As many bolts 28 as there are holes 26 formed in the head unit 21A,i.e., as many as the holes 26 formed in the head unit 21B, are fixed, asfastening members, to the head main body 11. Each bolt 28 is insertedinto one corresponding hole 26 in the head unit 21A, one correspondinghole 27 in the sealing member 20, and one corresponding hole 26 in thehead unit 21B. In addition, respective head portions of the bolts 28abut an end face of the head main body 11 on one side in the directionalong the longitudinal axis C. A single corresponding nut 29 is fastenedto each bolt 28 via screw-fitting, etc. at an end of the bolt 28opposite the head portion. Each nut 29 abuts the head main body 11 atthe end face opposite to the end face which abuts the head portion ofthe bolt 28.

The bolts 28 and the nuts 29 are fixed to the head main body 11 asdescribed above, so that the head main body 11 is fastened in thedirection along the longitudinal axis C by the bolts 28 and nuts 29. Inother words, the head main body 11 is compressed between the headportions of the bolts 28 and the nuts 29 in the direction along thelongitudinal axis C. The head units 21A and 21B are coupled to eachother through fastening involving use of the bolts 28 and the nuts 29.

In the present embodiment, since the bolts 28 and the nuts 29 areattached to the head main body 11 as described above, the bolts 28 andnuts 20 are provided on the inner circumferential side with respect tothe outer circumferential surface of each unit main body 23 of the headunits 21A, 21B and the nozzle 12. The bolts 28 and nuts 29 are formedbetween the head flow passage 16 (hollow 25) and the outercircumferential surface of the head main body 11 according to the radialdirection of the head main body 11. Therefore, in the presentembodiment, the coupling structure coupling the head units 21A and 21Bto each other is provided on the inner circumferential side with respectto the outer circumferential surface and the nozzles 12 in each unitmain body 23 of the head units 21A, 21B. That is, the coupling structure(coupling) is not formed on the outer circumferential surfaces of theunit main bodies 23 on which the nozzles 12 are arranged.

The bolts 28 and nuts 29 are formed of a conductive material. In thepresent embodiment, the head portion of the bolt 28 abuts one end faceof the head main body 11 in the direction along the longitudinal axis Cas described above. The nut 29 abuts the head main body 11 at the endface opposite to the end face which abuts the head portion of the bolt28. For this reason, in the present embodiment, the head units 21A and21B are electrically connected to each other via the bolts 28 and thenuts 29. Also, in each of the head units 21A and 21B, the unit main body23 is electrically connected to the nozzles 12. Therefore, when avoltage is applied to the electrospinning head 2 by the electric powersource 4 as described above, the nozzles 12 in the head unit 21A and thenozzles 12 in the head unit 21B come to have identical or substantiallyidentical electric potential to each other.

In the present embodiment, the plurality of head units 21A and 21B arearranged along the longitudinal axis C, and the head units 21A and 21Bare coupled to each other. For this reason, the size of the head mainbody 11 in the direction along the longitudinal axis C can be increased.In the head main body 11, which is large in size in the direction alongthe longitudinal axis C, a plurality of nozzles 12 are arranged alongthe longitudinal axis C. By configuring the head main body 11 asdescribed above, a film of the fiber 100, large in size in the directionalong the longitudinal axis C of the head main body 11, is appropriatelyformed. That is, a film of the fiber 100, large in size in its widthdirection, is appropriately formed.

In the present embodiment, since the plurality of nozzles 12 arearranged as described above, when the film of the fiber 100 is formed asdescribed above by the ejection of the raw material liquid from thenozzles 12, it is unnecessary to reciprocally move the nozzles 12 in thewidth direction of the film of the fiber 100, for example. Therefore, itis unnecessary to provide a driving system for moving the nozzles 12 inthe electrospinning apparatus 1. Therefore, in the electrospinningapparatus 1, its configuration, control system, etc. will not becomplicated.

In addition, in the present embodiment, the head units 21A and 21B arecoupled in a state where the hollows 25 of the unit main bodies 23 ofthe head units 21A and 21B communicate with each other. A head flowpassage 16 is then formed along the longitudinal axis C by the hollows25 of the unit main bodies 23 of the head units 21A and 21B. Since thehead flow passage 16 is formed as described above, in the presentembodiment, it is unnecessary to form, in a single member, a hole(hollow), large in size in the direction along the longitudinal axis C,in the formation of the head main body 11. Therefore, the manufacturingcosts of the head main body 11 and the electrospinning head 2 aresuppressed, and their productivity increases.

In the present embodiment, a space between the unit main bodies 23 ofthe head units 21A and 21B is maintained in a liquid-tight manner by thesealing member 20. The outflow of the raw material liquid from the headflow passage 16 to the outside of the head main body 11 is prevented ata coupling face P by the sealing member 20. For this reason, even withthe configuration where the head flow passage 16 is formed byconfiguring the hollows 25 of the unit main bodies 23 of the head units21A and 21B to communicate with each other, the outflow of the rawmaterial liquid from the head flow passage 16 is effectively prevented.

In the present embodiment, the head units 21A and 21B are electricallyconnected to each other via the bolts 28 and the nuts 29. In each of thehead units 21A and 21B, the unit main body 23 is electrically connectedto the nozzles 12. Therefore, when a voltage is applied from theelectric power source 4, each nozzle 12 of the head units 21A and 21Bcomes to have an identical or substantially identical electric potentialto each other by connecting the electric power source 4 to one of theunit main bodies 23 of the head units 21A, 21B. This preventscomplication of the configuration of the power feeding system thatapplies a voltage to the electrospinning head 2.

In the present embodiment, the bolts 28, the nuts 29, etc. are providedon the inner circumferential side with respect to the outercircumferential surface and the nozzles 12 in each unit main body 23 ofthe head units 21A, 21B. For this reason, even if the coupling structurefor coupling the head units 21A and 21B is provided, protruding portionsother than the nozzles 12 are not formed in the vicinity of the nozzles12 on the outer circumferential surface of the head main body 11.Therefore, the influence of the coupling structure on an electric fieldin the vicinity of the nozzles 12 is suppressed, even if the couplingstructure of the head units 21A and 21B is provided.

(Modifications)

In a first modification shown in FIGS. 6 to 9, nozzles 12A, 12B areprovided as the nozzles 12 on the outer circumferential surface of thehead main body 11. In this modification, the nozzles 12A and 12B arerespectively provided in plural numbers. In addition, in thismodification, a plurality of nozzles (first nozzles) 12A are arranged atthe same or substantially the same angular positions with respect to oneanother around the longitudinal axis C, and a plurality of nozzles(second nozzles) 12B are arranged at the same or substantially the sameangular positions with respect to one another around the longitudinalaxis C. Therefore, in this modification, the plurality of nozzles 12Aare arranged along the longitudinal axis C to form a nozzle row (firstnozzle row) 15A. Also, the plurality of nozzles 12B are arranged alongthe longitudinal axis C to form a nozzle row (second nozzle row) 15B.Here, FIG. 6 is a perspective diagram of the electrospinning head 2, andFIG. 7 shows a state where the electrospinning head 2 is viewed from adirection crossing (perpendicular or substantially perpendicular to) thelongitudinal axis C. FIG. 8 shows a cross-section of the electrospinninghead 2 parallel or substantially parallel to the longitudinal axis C,and FIG. 9 shows a cross-section of the electrospinning head 2perpendicular or substantially perpendicular to the longitudinal axis C.

The nozzles 12B are provided so as to be shifted with respect to thenozzles 12A around the longitudinal axis C. Therefore, the nozzle row15B is formed so as to be shifted with respect to the nozzle row 15A. Inthis modification, however, both the nozzles 12A and 12B are arranged onthe side where the collection body 5 is positioned with respect to thelongitudinal axis C. For example, the nozzles 12A are provided so as tobe shifted by about 60° from the nozzles 12B around the longitudinalaxis C. In an example of FIG. 6, etc., two sets of each nozzle 12A and12B are provided in the head unit 21A, and two sets of each nozzle 12Aand 12B are provided in the head unit 21B. Therefore, four sets of eachnozzle 12A and 12B are provided in the head main body 11. The numbers ofthe nozzles 12A and 12B provided respectively in the head units 21A and21B are not particularly limited, and it suffices that one or morenozzles 12A and one or more nozzles 12B are connected to each unit mainbody 23 of the head units 21A, 21B.

In the electrospinning head 2, a nozzle flow passage 17A is formed ineach nozzle 12A, and a nozzle flow passage 17B is formed in each nozzle12B. Each of the nozzle flow passages 17A and 17B communicates with thehead flow passage 16 and extends from the head flow passage 16 towardthe outer circumference side of the head main body 11. Each nozzle flowpassage 17A opens toward the outside at an ejection port 18A, and eachnozzle flow passage 17B opens toward the outside at an ejection port18B. In each nozzle 12A, the ejection port 18A is formed at a projectingend from the head main body 11. In each nozzle 12B, the ejection port18B is formed at a projecting end from the head main body 11.

The nozzles 12A and 12B are arranged in a zigzag manner on the outercircumferential surface of the head main body 11. The nozzles 12A andthe nozzles 12B are alternately arranged in the direction along thelongitudinal axis C. Therefore, one corresponding nozzle (second nozzle)12B is disposed between adjacent nozzles (first nozzles) in thedirection along the longitudinal axis C.

Also in this modification, the sealing member 20 is placed on a couplingface P of the head units 21A, 21B adjacent to each other. The couplingface P passes by a position away from both the nozzles 12A and 12B. Inthis modification, however, the nozzles 12A and 12B are arranged in azigzag manner as described above. For this reason, the coupling face Pis inclined relative to the longitudinal axis C. The normal linedirection of the coupling face P (the direction shown by the arrows N1and N2) is inclined relative to the longitudinal axis C.

In this modification, a nozzle 12B is disposed between nozzles 12Aadjacent to each other in the direction along the longitudinal axis C.Therefore, in the collection body or the substrate, the fiber 100 isdeposited by the nozzle 12B, even in a region between the nozzles 12Aadjacent to each other in the direction along the longitudinal axis C.This configuration effectively prevents the fiber 100 from being locallydeposited on the collection body 5 or the substrate. Therefore, it ispossible to effectively prevent a formed film of the fiber 100 fromhaving uneven thicknesses.

The coupling face P is inclined relative to the longitudinal axis C.Therefore, the head units 21A and 21B can be coupled at the couplingface P passing by a position located away from both the nozzles 12A and12B, even when the nozzles 12A and 12B are arranged in a zigzag manneras described above.

Furthermore, the coupling structure which couples the head units 21A and21B is not limited to the above-mentioned coupling structure using thebolts (fastening member) 28 and the nuts 29. For example, in a secondmodification shown in FIGS. 10 and 11, a male screw 41 is formed in theunit main body 23 of the head unit 21A. A female screw 42 is formed in aunit main body 23 of a head unit 21B. In this modification, the malescrew 41 is screw-fitted into the female screw 42, so that the headunits 21A and 21B are coupled to each other. Therefore, a couplingstructure (coupling) which couples the head units 21A and 21B is formedby the male screw 41 and the female screw 42. Here, FIG. 10 shows astate where the electrospinning head is viewed from a direction crossing(perpendicular or substantially perpendicular to) the longitudinal axisC, and the head units 21A and 21B are separated from each other. FIG. 11shows a cross-section parallel or substantially parallel to thelongitudinal axis C.

Also in this modification, the coupling structure formed from the malescrew 41 and the female screw 42 is provided on the inner circumferenceside with respect to the outer circumferential surface and the nozzles12 of each unit main body 23 of the head units 21A, 21B. The couplingstructure is formed between a head flow passage 16 (hollow 25) and theouter circumferential surface of a head main body 11, in the radialdirection of the head main body 11. Therefore, also in thismodification, the coupling structure which couples the head units 21Aand 21B to each other is not formed on the outer circumferential surfaceof the unit main body 23 on which the nozzles 12 are arranged. For thisreason, the influence of the coupling structure on an electric field inthe vicinity of the nozzles 12 is suppressed.

Furthermore, also in this modification, the sealing member 20 is placedon the coupling face P of the head units 21A, 21B. In this modification,a sealing member 20 is placed on the outer circumference side of themale screw of the head unit 21A. Also in this modification, the headunits 21A and 21B are electrically connected to each other via the malescrew 41 and the female screw 42, and the unit main body 23 iselectrically connected to the nozzles 12 in each head unit 21A and 21B.By virtue of the configuration described above, the electrospinning headaccording to this modification exerts similar function and advantageouseffects to those in the first embodiment.

In a modification, a male screw is formed in the head unit 21B, and afemale screw to be screw-fitted into the male screw is formed in thehead unit 21A.

In a third modification shown in FIGS. 12 and 13, a flange 45 is formedon each unit main body 23 of the head units 21A and 21B. In each of thehead units 21A and 21, the flange 45 protrudes to the outercircumference side in the outer circumferential surface of the unit mainbody 23. The flange 45 is, however, provided away from the nozzles 12,around the longitudinal axis C. The flange 45 is preferably provided onthe opposite side to a side where the nozzles 12 are positioned, withrespect to the longitudinal axis C. In an example, the flange 45 isdisposed away from the nozzles 12 by about 180° around the longitudinalaxis C. Here, FIG. 12 shows a state where the electrospinning head isviewed from a direction crossing (perpendicular or substantiallyperpendicular to) the longitudinal axis C. FIG. 13 shows a state wherethe electrospinning head is viewed from one side (the side where aninflow port 22 is positioned) in a direction along the longitudinal axisC.

In the head unit 21A, a flange 45 is formed at the end of the side wherethe head unit 21B is positioned in the direction along the longitudinalaxis C. In the head unit 21B, the flange 45 is formed at the end of theside where the head unit 21A is positioned in the direction along thelongitudinal axis C. In this modification, the flanges 45 of the headunits 21A, 21B abut each other. The flanges 45 of the head units 21A,21B are fastened in the direction along the longitudinal axis C by abolt 46 and a nut 47. The head units 21A and 21B are coupled to eachother by the fastening of the flanges 45 of the head units 21A, 21Bthrough use of the bolt 46 and the nut 47. Therefore, in thismodification, the coupling structure (coupling) which couples the headunits 21A and 21B is formed by the flanges 45, bolt 46 and nut 47.

In this modification, the coupling structure is provided on the outercircumferential surface of each unit main body 23 of the head units 21A,21B. However, the coupling structure including the flanges 45 isprovided away from the nozzles 12, around the longitudinal axis C. Forthis reason, in the vicinity of the nozzles 12 on the outercircumferential surface of the head main body 11, protruding portionsother than the nozzles 12 are not formed, similarly to the embodimentsdescribed above. Therefore, also in this modification, the influence ofthe coupling structure on an electric field in the vicinity of thenozzles 12 is suppressed.

Furthermore, also in this modification, the sealing member 20 is placedon a coupling face P of the head units 21A, 21B. In this modification,in the coupling face P, the sealing member 20 is placed on the innercircumference side of the flange 45 of the head unit 21A. Furthermore,in this modification, the head units 21A and 21B are electricallyconnected to each other via the flanges 45, and the unit main bodies 23in each of the head units 21A and 21B are electrically connected to thenozzles 12. By virtue of the configuration described above, theelectrospinning head according to this modification exerts similarfunction and advantageous effects to those in the first embodiment.

In another modification, the sealing member 20 is formed of a conductiverubber, etc., and has conductivity. In this case, the head units 21A and21B are electrically connected to each other via the sealing member 20.

In the above-mentioned embodiments, the electrospinning head 2 is formedfrom two head units 21A and 21B; however, the configuration thereof isnot limited to that disclosed above. In a fourth modification shown inFIG. 14, an electrospinning head 2 is formed from three head units 21Ato 21C. Also in this modification, the head units 21A to 21C arearranged along the longitudinal axis C and coupled to one another. Also,hollows 25 of unit main bodies 23 of the head units 21A to 21Ccommunicate with one another, and a head flow passage 16 is formed alongthe longitudinal axis C by the hollows 25 of the unit main bodies 23 ofthe head units 21A to 21C.

In this modification, the head units 21A and 21B are coupled to eachother in the same manner as in any one of the above-mentionedembodiments. The head units 21B and 21C are coupled to each other in thesame manner as in any one of the above-mentioned embodiments. When avoltage is applied to the electrospinning head 2 by an electric powersource 4, the nozzles 12 in the head units 21A to 21C come to have anidentical or substantially identical electric potential to one another.In this modification, a sealing member 20 is placed on a coupling faceof the head units 21A and 21B which are adjacent to each other, and thesealing member 20 is placed on a coupling face of the head units 21B and21C which are adjacent to each other. Also in this modification, similarfunction and advantageous effects to those of the above-mentionedembodiments are exerted.

Furthermore, in a modification, an electrospinning head 2 is formed bycoupling four or more head units 21 to one another. Also in this case,the head units 21 are coupled to one another to form a head flow passage16, in the same manner as in any one of the above-mentioned embodiments.

According to at least one embodiment or example of those describedabove, another head unit can be coupled to the head unit on at least oneside in the direction along the longitudinal axis C by the couplingstructure. The coupling structure couples a unit main body of saidanother head unit to the unit main body of the head unit, in a statewhere the hollow of the unit main body of the head unit communicateswith the hollow of the unit main body of said another head unit. Withthis configuration, it is possible to provide a head unit capable ofsuppressing the complexity of its configuration and its control systemin addition to an increase in manufacturing costs and a reduction inproductivity of the electrospinning head, and which can appropriatelyform a film of fiber large in size in the width direction.

In addition, according to at least one embodiment or example of thosedescribed above, the plurality of head units are coupled to one anotherby the coupling structure. The coupling structure couples a plurality ofhead units in a state where the hollows of their unit main bodiescommunicate with one another. Thereby, it is possible to provide anelectrospinning head which suppresses the complexity of itsconfiguration and its control system in addition to an increase inmanufacturing costs and a reduction in productivity of theelectrospinning head, and which can appropriately form a film of fiberlarge in size in the width direction.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A head unit comprising: a unit main body in whicha hollow configured to store a raw material liquid is formed along alongitudinal axis of the head unit; and a nozzle formed of a conductivematerial and provided on an outer circumferential surface of the unitmain body, the nozzle being configured to eject the raw material liquidsupplied through the hollow of the unit main body, and the head unitfurther comprising: a coupling structure capable of coupling anotherhead unit to the head unit on at least one side in a direction along thelongitudinal axis of the head unit, wherein the coupling structurecouples a unit main body of said another head unit to the unit main bodyof the head unit, in a state where the hollow of the unit main body ofthe head unit communicates with a hollow of the unit main body of saidanother head unit, so that a head flow passage is formed along thelongitudinal axis by the hollow of the head unit and the hollow of saidanother head unit which communicates with the hollow of the head unit.2. The head unit according to claim 1, comprising: plural of the nozzle,wherein the plural of the nozzle includes a first nozzle and a secondnozzle provided so as to be shifted with respect to the first nozzlearound the longitudinal axis of the head unit.
 3. An electrospinninghead comprising: a plurality of head units arranged along a longitudinalaxis of the electrospinning head; and a coupling structure that couplesthe plurality of head units to one another; each of the plurality ofhead units including: a unit main body in which a hollow configured tostore a raw material liquid is formed along the longitudinal axis; and anozzle formed of a conductive material and provided on an outercircumferential surface of the unit main body, the nozzle beingconfigured to eject the raw material liquid supplied through the hollowof the unit main body, wherein the coupling structure couples theplurality of head units in a state where the hollows of the unit mainbodies communicate with one another, so that a head flow passage isformed along the longitudinal axis by the hollows communicating with oneanother.
 4. The electrospinning head according to claim 3, wherein thenozzles in the plurality of head units are electrically connected to oneanother and come to have an identical electric potential to one anotherby application of a voltage.
 5. The electrospinning head according toclaim 3, wherein the coupling structure is provided on an innercircumference side with respect to the outer circumferential surface ofeach unit main body and each nozzle of in the plurality of head units.6. The electrospinning head according to claim 5, wherein in each of theunit main bodies of the plurality of head units, a hole is formed alongthe longitudinal axis, on the inner circumference side with respect tothe outer circumferential surface, the coupling structure includes afastening member to be inserted into the hole, and the plurality of headunits are coupled to one another by fastening of the fastening member.7. The electrospinning head according to claim 3, wherein the couplingstructure is provided away from the respective nozzles of the pluralityof head units around the longitudinal axis.
 8. The electrospinning headaccording to claim 3, further comprising: a sealing member providedbetween the head units adjacent to each other in a direction along thelongitudinal axis, the sealing member being configured to maintain aspace between the head units adjacent to each other in a liquid-tightmanner so as to prevent the raw material liquid from flowing out of thehead flow passage at a coupling face of the head units adjacent to eachother.
 9. The electrospinning head according to claim 3, wherein each ofthe plurality of head units includes plural of the nozzle, in each ofthe plurality of head units, the plural of the nozzle include a firstnozzle and a second nozzle provided so as to be shifted with respect tothe first nozzle around the longitudinal axis, the first nozzles of theplurality of head units form a first nozzle row in which the firstnozzles are arranged along the longitudinal axis, and the second nozzlesof the plurality of head units form a second nozzle row in which thesecond nozzles are arranged along the longitudinal axis, at a positionshifted with respect to the first nozzle row around the longitudinalaxis.
 10. The electrospinning head according to claim 9, wherein thefirst nozzles in the first nozzle row and the second nozzles in thesecond nozzle row are arranged in a zigzag manner, the first nozzles andthe second nozzles are alternately arranged in a direction along thelongitudinal axis, and a coupling face of the head units adjacent toeach other in the direction along the longitudinal axis and a normalline direction of the coupling face are respectively inclined relativeto the longitudinal axis.
 11. An electrospinning apparatus comprising:the electrospinning head according to claim 3; a supply sourceconfigured to supply the raw material liquid to the head flow passage ofthe electrospinning head; and an electric power source configured toapply a voltage to the electrospinning head.